Cibctjit breaker and method op tffakinq the same



Nov. 10, 1931. M. MALLORY 1,331,184

' CIRCUIT BREAKER AND METHOD OF MAKING THE SAME I Filed Sept. 24. 1928 Patented Nov. .10, 1931 UNITED STATES PATENT OFFICE MARION MALLORY, O1 TOLEDO, OHIO CIRCUIT BREAKER AND METHOD OF MING TEE SAME Application filed September 24, 1928. Serial nofsoasea.

arm is adapted to rock. It is impossible to make these stampings uniform, because of variations in the thickness or the hardness of the metal. T Then, too, a rubbing block must be secured to this"arm,to be engaged by the cam to open the primary circuit at the proper times. If the stationary contact point is grounded, the movable arm must be insulated from the chassis and the portion of the rubbing block which is engaged by the cam must be of insulating material. With these various sources of error, it has hitherto been necessary, in order to insure proper i ition at the proper time, to fit each circuit reaker individually and adjust thecontact points.

With theabove conditions in mind, the primary object of myinvention is to provide a circuit breaker which may be made according to standardized methods, in large numbers, and at a moderate cost, each one being made precisely like all the others so that practically no individual fitting or adjustment is necessary. In obtaining this object, the arm which carries the movable contact is molded from bakelite or similar material. 7

Another object in molding the movable member from such'materialis to make it light and to prevent a rebound when it is operated.

- Metal has such a high specific gravity that its inertia causes the circuit breaker to chatter when running, especially at high speed.

The specific construction of my improved circuit breaker and a practical method of making the same will be more'fully described in connection with the accompanying drawings, which illustrate the .preferred'embodiement of the invention.

In the drawings y Figure 1 represents .a diagrammatic view of the circuit breakerand the circuit with which it is associated.

Figure 2 is a perspective view of a molded. block constituting a part of the circuit breaker.

According to the invention, the circuit breaker comprises a block 5, in the form of a bell crank and composed of bakelite or other suitable insulating material, preferably molded. This bell crank is mounted on a pivot pin 6 and one of its arms is formed with an obliquely disposed slot 7 for receiving a flat spring 8. One end of this spring, adjacent the inner end of the slot 7, is secured to a contact 9, which extends through the end of the arm in the direction of the adjustable stationary contact 10. The intermediate portion of the's ring 8 is bent about the bearing portion or elliow 11 of the bell crank, and its other end is bent to engage about a pin 12, from which it is insulated by a lnishing 13.

The spring 8 constitutes a part of the 7 primary circuit, which extends from the battery 15 through a switch 16, a primary coil 17, spring 8, contact points 9 and 10 and thence to the battery 15 either through a ground or through an insulated connection. A condenser 18 is also connected to the circuit. The bell crank 5 is mounted incooperative relation to the usual cam 19, which is adapted to engage an inturned lip 20, formed on the end of the bell crank remote from the contact 9, to break the circuit at the proper time. 1

The bell crank 5 is preferably formed from bakelite orsimilar insulating material which may be molded with great accuracy to the form and size desired, so that the circuit breakers may l e-manufactured in large numbers at a low cost, all substantially alike,

.and may be readily installed withs ubstantially no individual adjustment. If desired, however, even greater accuracy in theshape and size of the block 21 may be secured by milling. The bell crank 5 is also extremely light and responds quickly to the influence of the cam 19 and the spring 8. The spring is so tensioned and so arranged with reference to the pivots 6 and 12 that the contacts 9 and 10 are held normally; closed, until opened by the engagement: ofthe camwith the lip 20.

While I have shown and described the preferred embodiment of the invention, it is to be understood that this is merely for the purpose of illustration and that various modifications may be made therein without any material departure from the scope of the invention as claimed.

What I claim is:

1. In a circuit breaker, the combination of a pivoted bell crank composed of insulating material and having a-slot extending obliquely through one of its arms, a spring extending about the outside of the elbow of said bell crank and through said slot and terminating at the end of said arm, said spring constituting part of the circuit, a fixed contact, a contact secured to the spring at the end of said'arm, said spring being so'tensioned as to normally hold the contacts closed, and means acting on the other arm of the bell crank for rocking the latter and thereby opening said contacts.

2. In a circuit breaker, the combination of a pivoted bell crank composed of insulating material andhaving a slot through one of its arms. a spring constituting part of the circuit and extending about the outside of the elbow of said bell crank and through said slot and terminating at the end of the arm. a contact secured to and extending through the end of the slotted arm and secured also to the end of the spring adiacent the slot. a fixed contact opposed to the contact 'on the arm. a pin to which one end of thespring is connected and rom which it is insulated. said s ring being so tensioned as to normally hold the contacts losed. and means acting on the other arm oi the bell crank for rocking the la ter and therebv opening said contacts.

3. A circuit breaker comprising a bell crank of insulating material. one arm of said bell crank having a lip projecting toward the other arm. a cam engageable with said lip to rock the bell crank in one direction to break the circuit, and a spring to return the bell crank and close the circuit, as the bell crank is released by the cam, said spring constituting a part of the circuit.

4. A circuit breaker comprlsing a bell' crank of insulating material having a slot extending obliquely through one of its arms,

the other arm of the bell crank having a lip projecting toward the other arm, a cam engageable with said lip to rock the bell crank in one direction to break the circuit, and a spring extending about the elbow of said bell crank and through said slot and tensioned so as to return the bell crank and close the circuit as the bell crank is released by the cam, said spring constituting a part of the circuit.

5. A circuit breaker comprising a pivoted member of insulating material having a slot extending obliquely through one end portion thereof, a conductore-xtending through said slot, and a contact secured to the pivoted member and to the end of the conductor adjacent said slot.

6. A circuit breaker comprising a pivoted member of insulating material, means for securin one contact and the adjacent portion of the clrcuit to one end of said member, and a cam en ageable directly with said member to roc the same to open the circuit.

7. A circuit breaker comprising a pivoted member of insulating material with a contact at one end, a spring mounted on said member and operable to rock the same in one direction, said spring being connected to said contact and constituting part of the circuit, and acam engageable directly with said member to rock said member in the other direction.

8. In a circuit breaker for ignition systems, a rotatable metallic cam, a rockable member having two extensions and composed of nonfiexible insulating material, a contact carried by one of said extensions, a fixed contact engageable by the first mentioned contact, the other of said extensions being engageable by the cam to open said contacts, anda spring connected to the movable contact to constitute part of the circuit, said spring beingso tensioned as to hold the oontactc normally closed.

9. In a circuit breaker for ignition systems, a rotatable metallic cam, a rockable member having two extensions at opposite sides of the cam and composed of non-flexible insulating material, a contact carried by one of said extensions, a fixed contact engageable by the first mentioned contact, the other of said extensions being engageable by the cam to open said contacts, and a spring extendingabout said rockable member outside of the angle defined by said extension, said spring being connected to the movable contact and constituting a part of the circuit and being so tensione'd asto hold the contacts normally closed..

10. In a circuit breaker for ignition systems, a rotatable metallic cam, a rockable member having two extensions in different directions from its axis and composed of non-flexible insulating material, a contact carried by one of said extensions, a fixed contact engageable by the first mentioned contact, the other of said extensions being engageable by the cam to open said contacts, and a spring extending about said rockable member outside of the sector within which the cam is located, said spring being connected to the movable contact and constituting part of the circuit and being so ten; sioned as to hold the contacts normally closed.

In testimony whereof I have hereunto signed my name to this specification.

MARION MALLORY. 

